XQuery is a functional query language used to get data processed in XML format. That SQL is for databases, is the same as for XML. It was developed for querying XML data.
XQuery is made of XPath expressions. This is a recommendation by W3C and is endorsed by all the main databases.
The definition given by the official documents about XQuery is as follows:
"XQuery is a standardized language for combining documents, databases, web sites and basically everything else. It's broadly implemented. It's efficient and simple to understand. XQuery eliminates proprietary middleware languages and Web Application creation languages. XQuery removes complex Java or C++ programs with a few lines of code. XQuery is simpler to work with and easier to maintain than many other alternatives."
XQuery is a functional language, which identifies and extracts elements and attributes from XML documents.
This may be used for such items as:
XQuery was developed by W3C, and was first released in 2007. On 23 January 2007, it was the recommendation of the W3C. XQuery 3.0 is an 8 April 2014 W3C Recommendation.